The goal of the research proposed here is to further illuminate the basic processes that contribute to and in this sense are responsible for, the behavior of the young developing duckling. Using the techniques of the operant conditioning laboratory to examine issues often considered in the domain of ethology, the research will employ imprinting techniques to examine three broad classes of behavior: aversive reactions, aggressive acts, and filial responses. In particular, the work will attempt to identify the factors that play a role in imprinting and its behavioral manifestations, and further our understanding of how those factors interact to generate the response patterns that are typically that are typically described as social attachment.